Description

Summary

This clinical trial is being conducted to learn more about a potential treatment (valoctocogene roxaparvovec) for people with severe hemophilia A. This research study will test and confirm the safety and effectiveness of the 6E13 vg/kg dose of the study drug (valoctocogene roxaparvovec) that contains the correct gene to make Factor VIII so that the body can make its own Factor VIII that functions properly. Only one dose of valoctocogene roxaparvovec is being given in this study, and this dose has been previously studied in another clinical trial in patients with hemophilia A. This is a phase 3 study which is meant to show that the study drug is safe and works to help treat hemophilia A. The study will see if liver cells are able to make Factor VIII that functions properly after receiving this study drug. The study will also examine the effects that the study drug has on how much Factor VIII concentrates patients have to inject into their veins and on their bleeding episodes after the study drug has been administered. Finally, the study will see if and how the body responds to the study drug - for example, whether liver cells become inflamed or whether the body makes antibodies (something the immune system makes to protect itself against things like bacteria and viruses) against the vector or the new Factor VIII gene.

Eligibility

You can join if…

Open to males ages 18 years and up

Males ≥ 18 years of age with hemophilia A and residual FVIII levels ≤ 1 IU/dL as evidenced by medical history, at the time of signing the informed consent.

Must have been on prophylactic FVIII replacement therapy for at least 12 months prior to study entry. High-quality, well-documented historical data concerning bleeding episodes and FVIII usage over the previous 12 months must be available.

Treated/exposed to FVIII concentrates or cryoprecipitate for a minimum of 150 exposure days (EDs).

No previous documented history of a detectable FVIII inhibitor, and results from a Bethesda assay or Bethesda assay with Nijmegen modification of less than 0.6 Bethesda Units (BU) (or less than 1.0 BU for laboratories with a historical lower sensitivity cutoff for inhibitor detection of 1.0 BU) on 2 consecutive occasions at least one week apart within the past 12 months (at least one of which should be tested at the central laboratory).

You CAN'T join if...

Detectable pre-existing antibodies to the AAV5 capsid.

Any evidence of active infection or any immunosuppressive disorder, including HIV infection.

Significant liver dysfunction with any of the following abnormal laboratory results:

ALT (alanine aminotransferase) > 1.25x ULN;

AST (aspartate aminotransferase) > 1.25x ULN;

GGT (gamma-glutamyltransferase) > 1.25x ULN;

Total bilirubin > 1.25x ULN;

Alkaline phosphatase > 1.25x ULN

INR (international normalized ratio) ≥ 1.4.

Subjects whose liver laboratory assessments fall outside of these ranges may undergo repeat testing of the entire liver test panel within the same Screening window and, if eligibility criteria are met on retest, may be enrolled after confirmation by the Medical Monitor.

Prior liver biopsy showing significant fibrosis of 3 or 4 as rated on a scale of 0-4 on the Batts-Ludwig (Batts 1995) or METAVIR (Bedossa 1996) scoring systems, or an equivalent grade of fibrosis if an alternative scale is used.

Active Hepatitis C as evidenced by detectable HCV RNA or currently on antiviral therapy.

Active malignancy, except non-melanoma skin cancer.

History of hepatic malignancy.

History of arterial or venous thromboembolic events (eg, deep vein thrombosis,nonhemorrhagic stroke, pulmonary embolism, myocardial infarction, arterial embolus),with the exception of catheter-associated thrombosis for which anti-thrombotic treatment is not currently ongoing.

Known inherited or acquired thrombophilia, including conditions associated with increased thromboembolic risk, such as atrial fibrillation.